There are many options available for birth control, and it can be confusing to sort through the different kinds. In order for it to be most effective for you, it has to be an option that works well for you.
There’s more to it than just how well it works to prevent pregnancy. For example, pills can work well and have other beneficial side effects, but if you are someone who can’t remember to take a pill every single day, it’s probably not the best choice. Likewise, abstinence (not having sexual intercourse) is 100% effective, free, and prevents sexually transmitted infections, but it’s not necessarily a realistic-or lifelong-option!
This discussion is going to be limited to reversible birth control methods, meaning ways to prevent pregnancy that can be stopped at anytime. So, what’s out there?
Barrier Methods
These are things like condoms, diaphragms, female condoms, and sponges. The barrier methods work by blocking the movement of semen into the female genital tract. They have to be used every single time, so they do take some planning—condoms need to be on hand, the diaphragm needsto be fitted and placed into the vagina. The big benefit to them is that using condoms consistently and correctly can decrease your risk of sexually transmitted infections (STIs), including HIV. You can also use condoms along with other forms of birth control- either as a back-up method, or to protect against STIs. They are also able to be purchased without a prescription and are inexpensive. The actual efficacy of male condoms is ~85%, meaning that 85 couples out of 100 using them will not get pregnant in a year (or 100 – 85 = 15 pregnancies per year). In theory, condoms used correctly and consistently- every single time- will be 98% effective (only 2 pregnancies)…but no one really lives in a perfect world!
The Pill, the Patch, and the Ring
These methods all work by giving you a dose of two hormones, estrogen and progestin. The combination of these hormones blocks the signals that would normally trigger ovulation, or the monthly release of an egg. There are many different kinds of pills, which need to be taken every day. For women who may not want to take a pill - or have a difficult time remembering to take it- there are other ways to take the hormones. The patch is a sticker that is placed on the skin for a week at a time, and the ring is a flexible, plastic ring that is placed in the vagina for 3 or 4 weeks at a time, and can be left in place during sex. The actual efficacy rate of pills, patches, and rings is 92%, meaning that 92 women out of 100 women using them will not get pregnant. But that’s 8 out of 100 that may get pregnant in a year.
Taken every day, perfectly with no missed or late pills, patches, or rings, these methods may be 99% effective.
All of these methods have the same side effects; most commonly, these are breakthrough bleeding or spotting, nausea, and breast tenderness. Because of the estrogen in these methods, these methods can increase the risk of developing blood clots in the legs or lungs. Women who have had a history of blood clots or strokes and women who smoke over the age of 35 should not take these methods. But it’s not all bad news: the pill, the patch, and the ring can improve acne, cramping, heavy periods, unwanted hair growth, and reduce the risk of uterine and ovarian cancers. If desired, they can also regulate whether and when periods occur; it’s possible to have a period once a month or once a year.
The Mini-Pill
These pills contain only one hormone, a progestin. They are much smaller doses that those in regular pills, which also contain estrogen. They work by thickening cervical mucus and preventing the sperm from reaching the egg. After taking a mini-pill, the effects wear off after ~22-24 hours- and they don’t always prevent the release of an egg, so it’s very important to take the mini-pill at the same time everyday for it to be effective in preventing pregnancy. Because of the decreased effectiveness compared to regular pills, it’s often recommended for women who cannot take regular pills, such as breastfeeding women or women who are at high risk of complications from regular pills.
The Emergency Birth Control Pill
These pills, which contain progestins (like the mini-pill, but higher doses), can be used to prevent pregnancy when another method may have failed. They work by preventing ovulation, or the release of an egg. If you are already pregnant, they will not cause a miscarriage or abortion. They are most effective at preventing pregnancy when taken as early as possible after sex, but they can be taken up to 5 days later. They may decrease the risk of pregnancy as much as 89%. Because of the cost and the way that they work, they are most useful for unexpected or emergency situations and shouldn’t be used as the main method of birth control.
The Shot (Depo-Provera)
This method is a hormone shot containing a progestin hormone. It works through a combination of actions: it prevents ovulation and thickens the cervical mucus. It is very effective- 97%, meaning 3 out of 100 women may get pregnant using it during the first year, and it can be a very private method to use- once you have taken the shot, no one else would know it. The main side effects are irregular bleeding or spotting, and most women who use Depo-Provera for 1 year will stop having menses at all. Sometimes after stopping the shot, it can take some time before periods return to normal. The shot can also cause some bone thinning, but this is reversed when women stop using the shot and does not seem to increase the risk of bone fractures.
The Implant
This method is similar to Depo-Provera, but instead of a big dose every three months, the small plastic rod releases a smaller amount of a progestin hormone continuously. The rod is placed into a woman’s arm in the office, and it can stay in place up to 3 years, making it a long-acting method birth control. It is also very effective- also <1% of women will become pregnant during the first year of use. It can also cause irregular bleeding or spotting as a side effect, similar to Depo-Provera, but these effects wear off very quickly when the implant is removed.
Intra-Uterine Contraception
This form of birth control is used by placing a contraceptive device into the uterus. There are two different types of intrauterine contraception that are most common in the US (see below). Both kinds are very effective, with <1% of women becoming pregnant during the first year. Both are also very safe to use, although there is a small risk of infection, especially at the time of placement- and can be used by most women, even women who are teenagers, have never been pregnant, or cannot take estrogens.
The Mirena IUS (for intra-uterine system) is a T-shaped piece of plastic that releases a progestin hormone into the uterine lining, and it prevents pregnancy by thickening cervical mucus and making the uterine lining so thin that a pregnancy cannot develop there. It can also decrease the amount of bleeding and cramping with periods. The Mirena can stay in place for 5 years. The Paragard IUD (intra-uterine device) is also a T-shaped piece of plastic, but instead of a hormone, it has copper on it that causes a reaction that kills sperm; it may also prevent pregnancies from implanting into the uterus. It may cause heavier periods. The Paragard can stay in place up to 10 years.
Both of these methods can be stopped at any time by making an appointment to have the devices removed, and the effects wear off very quickly.
As you can see, there are many methods out there. If you’re interested in any of these forms of birth control, or if you have any questions, you should make an appointment to talk with your doctor.
by: Gretchen Reinhart, M.D.